Platelet abnormalities in aggressive subjects with mental deficiency.

Platelet 3H-imipramine (3H-IMI) binding and platelet sulfotransferase (ST) activity, taken as markers of the serotonin (5-HT) and sulfated neurotransmitters (tyramine, dopamine, serotonin, noradrenaline), respectively, were evaluated in 14 severely aggressive subjects institutionalized since childhood for mental retardation and in an equal number of healthy controls. The results showed the presence of a lower number of 3H-IMI binding sites and a higher ST activity in the patients as compared with controls. These data provide supporting evidence for the hypothesis of an abnormality of the 5-HT system and suggest possible dysfunctions of dopamine and sulfated amines in aggressive behavior, at least as reflected by platelet markers.

Psychotic symptoms in mood disorders: Evaluation of 159 inpatients.

The authors investigated the historical and clinical variables of 159 inpatients affected by mood disorders in order to identify variables which might differentiate psychotic from non-psychotic forms. The results showed that 32% of the patients had psychotic symptoms. Although no significant difference was detected with regard to the severity of depression, psychotic depressives were younger and had a lower age at onset, as well as a shorter episode length. These features suggest that depression may express itself with or without psychotic symptoms, according to the different individual and, perhaps, biological substrate. Taken together, our findings seem to indicate that psychotic depression should not be considered a separate clinical entity, but a subtype of mood disorders.

Platelet markers in suicide attempters.

1. The authors measured 3H-imipramine (3H-IMI) binding and serotonin (5HT) uptake parameters as well as sulphotransferase activity in platelets of suicide attempters. 2. Platelet 3H-IMI binding sites and 5HT uptake are related to similar sites and processes present in the brain, and sulphotransferase (ST) is an enzyme involved in the catabolism of cathecholamines. 3. The results showed the presence of a decreased density of both 3H-IMI binding and of 5HT uptake sites, with no change in ST activity in suicide attempters, as compared with healthy controls. 4. The reduced 3H-IMI binding and 5HT uptake may be related to a hypofunction of presynaptic serotonergic mechanisms which might be altered in suicidal behavior.